Monitoring transgene expression levels in different genotypes of field grown maize (Zea mays L.)

• Published in: South African journal of botany Vol. 84; pp. 6 - 10
• Main Authors: Bakó, A., Gell, G., Zámbó, Á., Spitkó, T., Pók, I., Pintér, J., Balázs, E.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.01.2013
• Subjects: backcrossing; corn; CP4 epsp; Cry3Bb1; gene expression; genetic background; Herbicide tolerance; herbicides; inbred lines; insect pests; leaves; Maize; monitoring; plant development; ribosomal RNA; statistical analysis; Transgene expression profile; transgenes; transgenic plants; Zea mays; V4-6; R3; Bt; Cry3Bb1; CV; R6; Transgene expression profile; Herbicide tolerance; CP4 epsps; Maize; R0; CP4 epsp
• ISSN: 0254-6299; 1727-9321
• DOI: 10.1016/j.sajb.2012.09.005

Transgenes in commercially available genetically modified plants are generally controlled by strong constitutive promoters to ensure a high level of expression at all stages of cultivation. Constitutive promoters however are influenced by a wide range of factors, and expression profiles of the transgenes in multiple genetic backgrounds have not yet been extensively studied. In this study a powerful expression profiling methodology for transgenic maize (Zea mays L.) is demonstrated on a large scale, analysing thousands of data points from three genotypes of herbicide and insect pest tolerant transgenic maize. Martonvásár inbred lines were crossed with LH244 maize line containing the MON 88017 events, and leaf tissue from the sixth backcross generation was sampled at four relevant phenological phases. Relative expression levels were determined using 18S rRNA as a reference and detailed statistical analysis performed. Expression levels of both transgenes are varied throughout plant development, and the interaction between the genetic background and phenophase are significant (p<0.05). Expression is present at a significant level throughout all the phenological stages. We found that the genetic background has a significant (p<0.01) effect on transgene expression levels in the case of the CP4epsps transgene, but not in the case of cry3Bb1, implying that the sensitivity of different constitutive promoter constructs to the effects of the genetic background is different. ► We evaluate expression levels of two different transgenes in maize genotypes. ► These maize lines containing the MON 88017 events, leaf tissue from 6 BC were examined. ► Genetic background has a significant effect on transgene expression level of CP4epsps. ► Constitutive promoters have different sensitivity to the effect of genetic background.